/*
 * Copyright (C) 2017 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.android.volley.toolbox;

import com.android.volley.AuthFailureError;
import com.android.volley.Header;
import com.android.volley.Request;
import com.android.volley.VolleyLog;

import java.io.IOException;
import java.io.InputStream;
import java.net.SocketTimeoutException;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;

import org.apache.http.ProtocolVersion;
import org.apache.http.StatusLine;
import org.apache.http.entity.BasicHttpEntity;
import org.apache.http.message.BasicHeader;
import org.apache.http.message.BasicHttpResponse;
import org.apache.http.message.BasicStatusLine;

/**
 * An HTTP stack abstraction.
 * 提供一个http请求抽象方法，用于用户自己实现该方法
 * 提供一个默认的http执行请求，依赖的是org.apache.http 库，未来可能被移除
 */
@SuppressWarnings("deprecation") // for HttpStack
public abstract class BaseHttpStack implements HttpStack
{
    
    /**
     * Performs an HTTP request with the given parameters.
     * 使用给定的参数执行HTTP请求
     * <p>A GET request is sent if request.getPostBody() == null. A POST request is sent otherwise,
     * and the Content-Type header is set to request.getPostBodyContentType().
     * 如果 request.getPostBody() == null则是一个get请求，否则是一个post请求，以及请求内容类型在request.getPostBodyContentType()中设置
     *
     * @param request           the request to perform  执行请求
     * @param additionalHeaders additional headers to be sent together with {@link
     *                          Request#getHeaders()}   请求头
     * @return the {@link HttpResponse}  返回一个http响应
     * @throws SocketTimeoutException if the request times out  请求超时异常
     * @throws IOException            if another I/O error occurs during the request  读写异常
     * @throws AuthFailureError       if an authentication failure occurs during the request  验证失败错误
     */
    public abstract HttpResponse executeRequest(Request<?> request, Map<String, String> additionalHeaders) throws IOException, AuthFailureError;
    
    /**
     * @deprecated use {@link #executeRequest} instead to avoid a dependency on the deprecated
     * Apache HTTP library. Nothing in Volley's own source calls this method. However, since
     * {@link BasicNetwork#mHttpStack} is exposed to subclasses, we provide this implementation
     * in case legacy client apps are dependent on that field. This method may be removed in a
     * future release of Volley.
     */
    @Deprecated
    @Override
    public final org.apache.http.HttpResponse performRequest(Request<?> request, Map<String, String> additionalHeaders) throws IOException, AuthFailureError
    {
        //执行http请求，获取响应数据
        HttpResponse response = executeRequest(request, additionalHeaders);
        //添加相关参数
        //http协议版本
        ProtocolVersion protocolVersion = new ProtocolVersion("HTTP", 1, 1);
        VolleyLog.e("BaseHttpStack,ProtocolVersion:" + protocolVersion.toString());
        StatusLine statusLine = new BasicStatusLine(protocolVersion, response.getStatusCode(), /* reasonPhrase= */ "");
        VolleyLog.e("BaseHttpStack,statusLine:" + statusLine.toString());
        BasicHttpResponse apacheResponse = new BasicHttpResponse(statusLine);
        VolleyLog.e("BaseHttpStack,apacheResponse:" + apacheResponse.toString());
        List<org.apache.http.Header> headers = new ArrayList<>();
        for (Header header : response.getHeaders())
        {
            VolleyLog.e("BaseHttpStack,header.getName():" + header.getName()+",header.getValue():"+header.getValue());
            headers.add(new BasicHeader(header.getName(), header.getValue()));
        }
        apacheResponse.setHeaders(headers.toArray(new org.apache.http.Header[headers.size()]));
        InputStream responseStream = response.getContent();
        if (responseStream != null)
        {
            BasicHttpEntity entity = new BasicHttpEntity();
            entity.setContent(responseStream);
            entity.setContentLength(response.getContentLength());
            apacheResponse.setEntity(entity);
        }
        VolleyLog.e("BaseHttpStack,apacheResponse:" + apacheResponse);
        return apacheResponse;
    }
}
